Identification of the 5g-4f Rydberg-Rydberg transition of the NO molecule

Abstract
The 4 mu m band radiation from high temperature air investigated by Wray and Taylor in 1969 is interpreted as 5g-4f emission of the NO molecule. Position, fine-structure and intensity of the band are in excellent agreement with previous knowledge on the 4f complex of NO and with theoretical 5g energies and 5g-4f oscillator strengths.